Resistance unit.



H. J. WIEGAND.

RESISTANCE UNIT.

APPLICATION FILED MAILZZ, 1911.

1,1 20,259. Patented Dec. 8, 1914.

a mm of which the following "UNITED STATES PATENT ornion.

HENRY J'. WIEGAND, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER-HAMMER I MFG. (30., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

RESISTANCE UNIT.

To all whom it may concern: 7

Be it known thatI, HENRY J. WIEGAND, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Resistance Units,

is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a part of this specification.

My invention relates to resistance units.

It is especially suitable for use in connection with electrically heated devices and I shall, describe it as applied to this use but it is obviously not so limited and in its various adaptations to practice may assume various other forms and be used in various other relations. I

My invention has among its various objects to provide a resistance unit which will directly conduct the heat to the object to be heated, {which may be made in various forms for use in different constructions, which will distribute the heat where it is most-ne'eded', which will occupy the minimum of space, which is a unitary structure and capable of being removed when desired, which'will be rugged and have long life in service, and which at the same time will ture. s

o Other objects and advantages of my invention will hereafter appear.

cost but little to' manufac- In order to illustrate theprinciple of my I have in the accompanying invention, views shown several forms which a heating unit constructed in accordance with my invention may assume in practice. My invention is, however, in no wise limited in its use to these specific forms and may assume various other forms and be adapted to various other. uses. I

Figure 1 shows a top plan View of one form of resistance unit. Fig. 2 shows a sectional view of the same in position in an iron. Fig. 3 shows a sectional view of a unit inclosed in a modified form of casingQ Figs. 4 and 5 show In heating element.

The resistance unit shownin Fig. 1 is adapted to use as a heating element for an electric iron and is provided with a fiat dified formsf' 'of a Specification of Letters Patent.

Application filed March 22,1911.

' the notches to, the places back of the base 1,

' PatentedDec. s, 1914. Serial No. 516,273.

'base 1 of suitable insulating material, so

shaped as to conform to the inside of an iron. Holes 2 are the center line of of the center line of the iron longitudinally preferably arranged near the base to permit bolts hereinafter described to pass through the disposed ears 5 are struck up from the base 1. In a preferred form these ears 5 are approximately opposite projections 6 between 3 and are provided with rounded portions 7 at their ends similar to the rounded portions 4 of the notches 3.

A reflex resistance material 8, which may consist of a single length ofwire, is laced back and forth transversely of the base in convoluti'ons 9 which extend up one side of the base across site side. The outer ends of each convolu- While the inner ends are looped around the ears 5, the resistance material passing through the rounded portions 4 and 7 The ends .of the" resistance material are passed through adjacent perforations 10, near the and are thus brought close together in order to enable them to be readily connected to a suitable source of current supply.

In order to obtain a proper distribution the heat supplied to the iron, it is desirable to heat certain portions of the object to be heated to a greater heat than other portions. By my improved construction I am able to increase the heat supplied to these portions by pressing the reflected resistance material more closely together at these points. I have illustrated this in Fig.1 in which it is to be noted that the'refiexed resistance material is pressed close together at the tip and around the curved portions the top and down-the oppoof the periphery of the iron where the greatest heat is required, while the reflexed resistance material near the center and back of the iron is compressed less closely. Obviany portion lncreaslng increase the heat supplied to of any object to be heated by the closeness of the reflexed material or the convolutioli's at that point, and. I may decrease the heat by increasing the distance between the same.

In order to procure the ously I may greatest heating efliciency of a resistance umt, it is hlghly desirable to convey the heat to the object to be heated by conduction rather than radiation so that the losses of heat by radiation are avoided. A heating element constructed in accordance with my invention is especially efficient in this respect, since due to its compact and unitary construction it is capable of being brought; into immediate .the

proximity to the object to be heated so that heat supplied by the unit can pass by conduction; directly to the object to be heated.

In Fig. 2, I have as an example illustrated on an enlargedscale a unit constructed in accordance with my invention in position in a laundry iron. Above the resistance material 8 is placed .a sheet of mica or other insulating material 11, similar in shape to 'for instance, taps 15 on the base 1. Below the base 1 is placed a similar sheet of insulating material 12. After the unit has sheets it is tightly clamped between the heat .retaining plate 13 of the iron and the bottom of the iron 14 by any suitable means, as

' which pass throughperforations in the, re-

. stices between the reflexed taining plate 13,}the base 1, the sheets of lation which may be used, the heating unit' is brought into immediate proxlmlty to the the iron let, and since the the mica to fill the interportions of 'the resistance material loss of heat by radiation is avoided and the heat-developed by the resistance material isv very directly and therefore very efficiently conducted to the bottom plate of pressure causes surface to-be heated.

In Fig. 3, I have shown, scale, cordance with my invention inclosed in one form of suitable casing. In this figure the base is' shown at 1, the resistance material carried thereby is shown at 8, and the sheets of insulating material above and below the same are'shown at 11 and 12 respectively. When so inclosed the ,unit is placed between thin sheets 17 'and 18 of a soft metal, for instance as copper or aluminum, which is softer than the metal of which been placed betweenthese threaded bolts 16 on an enlarged" a resistance unit constructed 1n ac-- the resistance material 8v is composed, yet

sufiiciently hard to withstand the working temperature of the iron. These sheets of soft metal are pressed together and as a result of this pressure, portions of the insulating material and the soft metal are forced together between the refiexed resistance material 8 so as to form a unitary, compact and air-tight structure. The portions of the metal sheets directly above and below the resistance material 8 will on account ofthe hardness of the material 8 not be compressed as will that portion between the wires, but will form slight ridges those indicated at 19. The edges of the soft metal sheets may beclamped on each other as shown at 20 in Fig. 3, or may be desired fashion, de-

secured together 1n any pending upon the circumstances and the use for which the particular element is designed. As aresult ofpressing this soft metal on both sides of the heating unit, the unit is inclosed hermetically, and when heated is adapted to transmit its heatby conduction directly throughthe soft metal sheets 17 and 18 to the object to be heated. Further, when a :heating unit inclosed in such a soft metal casing is clamped in an iron as shown'in. Fig. 2, the corrugated surfaces of the soft metal plates 17 and 18 tend to conform to the clamping surfaces, andthus assist in increasing the efiiciency of the unit by increasing its ability to conduct the heat directly to the object to be heated.

In Fig. 4 I have shown a modified form of a heatingelenient constructed in accordance with my invention in which the base 1 is annular in form-.and provided with radially extending convolutions of reflected reslstance material 8, the convolutions of the above the material 8 such assame being looped over projections on the inner and outerperipheries of the base in a similar manner to that described in con- -nection with Fig. 1. I

In Fig. 5 I have shown a still further modification of a hea'ting'element constructed inaccordance with my invention wherein a unit of a circular shape is built up of a series of rectangular shaped units. It is obvious that a heating element of any desiredshape may; be built up, since units constructed in accordance-with my inventiontion may assume any desired shape whether in a single plane or curved, and

consequently may be adapted to many and diverse uses.

All of these for s and uses fall within the scope and foret ought'of. my invention, which, although I have described it in this application as applied to several forms of resistance 'units,'is not in any way limited to these specific forms, since these forms havebeen chosenfibut illustrative of the capable of being adapted to many anddi-' verse "forms and uses.

What I claim as new and desire to secure by Letters Patent isas follows 1. In a resistance unit, a base having in-' tegral peripheral projections thereon lying substantially in the plane of the base, and a resistance material laced in convolutions upon said base and looped ,over' said projections.

2. In a resistance unit, a base having integral projections formed thereon and ears struck up therefrom, and a resistance material laced in convolutions upon said base and alternately engaging said projections and said ears.

3. In av resistance unit, a base having integral projections formed .thereon and ears struck up therefrom, and a reflexed resistance material laced in convolutions upon said base, the outer ends of the convolutions engaging said projections and the inner ends being looped over said ears.

4. In a resistance unit, a base having a notched edge and ears struck up from the body portion thereof, and a single length of reflexed resistance material laced in convolutions upon said base, the outer ends of the convolutions' passing through the notches in the edge thereof and the inner ends being looped over said ears.

5., In a resistance unit,a base having projections and ears formed thereon, and a single length of reflexed resistance wire wound in convolutions transversely across said base and looped over the projections and the ears, the portions of thereflexed wire near the edge of the base being pressed closer together than the portions near the center of the base.

6. In a resistance element, in combination, a sheet of insulation having projections integral therewith, and a reflexed conducting wire having relatively small convolutions and being reflexed in relatively large convolutions on one side ofsaid sheet and engaging the projections thereon to form a sub: stantial unitary unit, said 'convolutions lying in a single plane and resting fiat upon the surface thereof.

7. In a resistance unit, an insulating base having a notched edge and a plurality of centrally located series of cars struck up from the body portion thereof, and a re-' flexed resistance material woundin convolutions up one side of said base, across one end of the same and down the opposite side, certain of said convolutions alternately passing. through said said ears.

. passing through said notches notches and around 8. In a resistance unit, a base having a.

notched edge and a plurality of series of ears struck up from the body portion there:

of along the middle of the base, said ears being spaced from each other length-of resistance materlal alternately and engaging said ears, said resistance material being wound up one side of. the base, across the end of the same'and down the opposite side and having its ends'broughtout at one end of the base in. close proximity.

9. A resistancecomprising a wire mat of a single thickness divided into two substantially longitudinal sections connected only at one end and formed of a continuous reflex .wire having relatively small convolutions terminating in close proximity.

10. In a resistance unit, an insulating base, ried upon one surface thereof and interlocked therewith, said resistance being divided into two substantially longitudinal sections connected only at one end and formed of a continuous reflexed wire having relatively small convolutions terminating in close proximity.

11. In a resistance unit, a base, a resistance material carried thereon, and a soft metal casing inclosing the same and compressed thereon until the metal of the resist-' ance material is partially surrounded by the metal of the metallic casing.

12. In a resistance unit, a base, a resistance material mounted thereon and laced in convolutions thereupon, means for insulating said resistance material, and a'soft metal casing inclosing the same and pressed into intimate heat conducting relation with respect to said resistance material and conforming to the convolutions of said resistance material. 13. A resistance unit having a flat base, peripheral projections on said base extending in the plane of said base, attaching means for an electrical conductor arranged on said base and spaced from the periphery thereof, said attaching means being adapted to lie substantially in the plane of the base, an electric resistance element arranged in convolutions on said base and held thereto by being alternately passed over said radial projections and said attaching means. v

In witness whereof, I have hereunto subscribed my name in the presence of two witnesses.

Witnesses:

M. L. FENNs, AIJERED HALVERSON.

and a reflexed resistance material car-" HENRY J. wIE ANn.

and a single It is hereby certified that in Letters Patent No. 1,120,259, granted December 8, 1914, upon the application of Henry J. Wiegand, of Milwaukee, Wisconsin, for an improvement in Resistance Units, errors appear in the printed specification requiring. correction as follows: Page 1, line 95, and page 2, line 106, forv the Word reflected read reflected; page 1, second column, second occurrence, for the lineindicating numeral 65 read 85; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 2nd day of February, A. 1)., i915.

[SEAL.] a. n HrrErmAn,

Acting Commissioner of Patents. 

